This invention relates to a method and apparatus for supplying metal coils to a processing station. More particularly, the invention relates to a method in which and to apparatus by means of which groups or stacks of coils are conveyed in following order to a destacking station, whereat each group is destacked by mechanical lifting means, more specifically, a lifting head, following which the coils are conveyed individually to the processing station.
Metal coils are produced by slitting sheet metal with a slitter as it is removed from a roll, and winding the metal strips from the slitter onto a cylindrical winding drum of a coil winder, rotating the drum about a horizontal axis. A group of annular coils is formed on the winding drum in this manner, in adjacent side-by-side relation to each other. There may be, for example, as many as 21 adjacent coils in the group. Orders are filled as the coils are produced, and for this purpose, the coils are supplied to a packaging line.
The packaging line includes one or more processing or operating stations, where packaging operations are performed, a conveyor line for supplying coils to the processing station or stations, and a mandrel for supplying coils to the conveyor line. The first processing station commonly is a banding station, at which bands are fastened around the coils to secure the loops or spiral windings of each coil together. The banded coils may be conveyed to a second station, at which they are palletized.
Each group of coils as produced is removed from the winding drum for supply to the packaging line by sliding onto an adjacent mandrel registering with the drum. The mandrel subsequently is moved into a position of registry with a then horizontally disposed movable spindle on a rotatable vertically disposed loading section of the packaging conveyor line.
The practice in the industry has been to manually separate on the mandrel and transfer to the spindle one coil at a time. The loading section of the conveyor line, bearing a single coil, is rotated through an angle of 90.degree., from the vertically disposed transfer position to a horizontally disposed conveying position, from whence the coil is conveyed individually on the conveyor line to a processing station. The process is repeated until all of the coils in the group have been placed on the conveyor line.
Employing the foregoing method, wherein the conveyor line is loaded with successive individual coils, considerable time and labor is required for the coil transfer operations, a relatively long conveyor line is required to accommodate the production of the slitter, and backups are frequent and result in excessive amounts of down time in the slitting operation. The provision of increased conveyor length or storage space on the conveyor line or in adjacent areas requires excessive plant space and/or additional storage and/or conveying facilities and apparatus.